Distributed capacitive/resistive electronic device

ABSTRACT

A distributed capacitive/resistive electronic device. An electronic device is described which includes a dielectric substrate, a first resistive component, a second resistive component, and a connecting component. The first resistive component is affixed to a first side of the dielectric substrate. The second resistive component is affixed to a second side of the dielectric substrate, wherein the second side is oppositely located from the first side. The connecting component is affixed to the dielectric substrate, wherein the connecting component electrically connects the first resistive component to the second resistive component, wherein the connecting component is electrically connectable to other electronic circuitry, and wherein, at a location removed from the connecting component, the second resistive component is electrically connectable to other electronic circuitry.

FIELD

[0001] The present invention relates generally to distributed electronicdevices.

BACKGROUND

[0002] In many high-frequency applications, a transmission line medium,as for example a coax cable or a strip line, is used so that one part ofthe system can be physically located at some distance from another part.Such an application could be, for example, the testing of a targetdevice by a test system by connecting probes to the target device withtransmission lines interconnecting the probes to the test system.Ideally such probes should detect and replicate the high speedelectronic signals present in the target device with a minimumdisturbance of the signal and a maximum fidelity of replication. Thesedevices are commonly used for analyzing signals detected by electronicmeasurement equipment, including, for example, oscilloscopes and logicanalyzers.

[0003] The usefulness of a probe depends upon the range of frequenciesfor which the response is true to the detected signal, the accuracy ofreplication, and the extent to which the probe detects the signalwithout detrimentally affecting the operation of the system or circuitbeing probed. If the input impedance of the combined probe and end-usedevice is the same order of magnitude as that of the circuit or systembeing probed, it may cause errors in the replication of the signal or achange in the operation of the circuit or system resulting in erroneousoutput or circuit malfunction. High probe tip capacitance will alsocause circuit loading problems at higher frequencies. Designing theprobe to have low capacitance and an input impedance which is highrelative to the impedance of the circuit being probed at the point ofprobing has been the common protection against these errors. This highimpedance results in only a small current to flow through the probe,allowing the target device to operate relatively undisturbed.

[0004] One measure of a probe is its intrusiveness or loading which isdependent upon the capacitance of the probe in parallel with the sourceresistance of the circuit under test. The capacitive reactance varies asa function of frequency resulting in the impedance of the probe alsovarying with frequency. The loading of previously available probes hasbeen limited, because the impedance of the probes falls at highfrequencies. Minimizing the capacitance of the probe has been onesolution for reducing the loading of the probe. Compensating for probetip capacitance by using active electronics at the probe tip is analternative which has been used for extending the effective bandwidth ofthe probe tip. Such compensation, however, has generally resulted in abulky and easily damaged probe tip.

[0005] Typical previously available probes included high resistanceprobes which minimized resistive loading and had high input impedance atD.C, but which had an impedance that fell off rapidly with increasingfrequency due to high input capacitance. High impedance cable was usedwith these probes to minimize capacitance, but this cable was very lossyat high frequencies, limiting bandwidth. Such probes also required themeasuring instrument to have a high impedance.

[0006] Also previously available were passive or resistive dividerprobes which had the lowest input capacitances available in a probe andtherefore had a very broad bandwidth. However, the low input resistancecould cause problems with resistive loading which could force thecircuit under test into saturation, nonlinear operation, or to stopoperating completely. Resistive divider probes in general do not haveany inherent ability to compensated for transmission line losses.

[0007] Still other probes were active field effect transistor probeswhich had active electronics at the probe tip to compensate for loadingproblems due to low input impedance. These probes had a higher inputimpedance than the resistive divider probes and a lower capacitance thanthe high impedance probes, but were limited in bandwidth due to thefield effect transistors. They were also bulky and easily damaged.

[0008] In other fields, a concept called pole-zero cancellation has beenknown. One application in which the concept was used was in a system formeasuring heart rate disclosed by Lanny L. Lewyn in U.S. Pat. No.4,260,951 entitled “Measurement System Having Pole Zero Cancellation”.In that system, pole-zero cancellation was used to cancel the longdifferentiation time constant so as to remove undesired shaping of theheart pressure wave caused by the second order feedback loop. Thisallowed the waveform to be refined so that it could enable greateraccuracy in measuring the heart rate.

[0009] More recently, wide bandwidth probes with pole-zero cancellationhave been utilized in probe tips. In U.S. Pat. No. 4,743,839entitled“Wide Bandwidth probe Using Pole-Zero Cancellation” by KennethRush, a pair of tip components and a pair of feedback components areutilized to obtain pole-zero cancellation. Values for the components arechosen such that a zero created by an RC circuit at the tip of the probeoccurs at the same frequency as the pole created by a feedback circuit.The result of this design is probe circuitry that has constant gain overall frequencies.

[0010] In such high-frequency probing applications, a transmission linemedium, as for example a coax cable or strip-line, is used so that thetest equipment can be physically located at some distance from thetarget device to be probed. However, the transmission line impedance istypically low compared to that of the target device which can result inunacceptable loading of the target. To isolate the target device fromthe loading effects of the transmission line, passive networks at orvery near the target are typically used. These isolation networks raisethe impedance of the transmission line as seen by the target at the costof reducing the signal strength as seen by the test equipment at theother end of the transmission line.

[0011] The transmission line medium typically has a measurable,frequency dependent insertion loss due to the effects of skin effect anda lossy dielectric medium. If insertion losses occur at frequencies lowenough to be in the frequency band of measurement, these losses canresult in an attenuation of the signal, as well as a distortion of thewaveform with associated measurement error. It is therefore, desirablein many applications to compensate for these transmission line mediumlosses in order to achieve a higher usable bandwidth for the system.

[0012] The frequency characteristics of transmission line insertionlosses are not simple poles. A generally accepted formula for describingthe frequency characteristics of the insertion loss is a magnituderoll-off as a function of the square root of the frequency of interest.While pole-zero compensation circuits can be used to improve lossytransmission line response, the loss characteristic of the line is not asimple pole circuit falling off at 20 dB/decade. As such, the losscharacteristics of the line cannot be adequately compensated for bysimply using a circuit having a zero at the appropriate frequency.

SUMMARY

[0013] In representative embodiments, a distributed capacitive/resistiveelectronic device is disclosed. The electronic device comprises adielectric substrate, a first resistive component, a second resistivecomponent, and a connecting component. The first resistive component isaffixed to a first side of the dielectric substrate. The secondresistive component is affixed to a second side of the dielectricsubstrate, wherein the second side is oppositely located from the firstside. The connecting component is affixed to the dielectric substrate,wherein the connecting component electrically connects the firstresistive component to the second resistive component, wherein theconnecting component is electrically connectable to other electroniccircuitry, and wherein, at a location removed from the connectingcomponent, the second resistive component is electrically connectable toother electronic circuitry.

[0014] Other aspects and advantages of the present invention will becomeapparent from the following detailed description, taken in conjunctionwith the accompanying drawings, illustrating by way of example theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings provide visual representations whichwill be used to more fully describe the invention and can be used bythose skilled in the art to better understand it and its inherentadvantages. In these drawings, like reference numerals identifycorresponding elements.

[0016]FIG. 1 is a drawing of a block diagram of an embodiment of acompensated probe network consistent with the teachings of the presentpatent document.

[0017]FIG. 2 is a drawing of an embodiment of a probe tip network asshown in FIG. 1.

[0018]FIG. 3 is a drawing of an embodiment of a connecting transmissionline as shown in FIG. 1.

[0019]FIG. 4 is a drawing of an embodiment of a termination network asshown in FIG. 1.

[0020]FIG. 5 is a drawing of an embodiment of an amplifier as shown inFIG. 1.

[0021]FIG. 6 is a drawing of a transfer function of a lossy transmissionline vs. frequency of the embodiment of the connecting transmission lineas shown in FIG. 3.

[0022]FIG. 7A is a drawing of an embodiment of another probe tip networkas shown in FIG. 1.

[0023]FIG. 7B is a drawing of an embodiment of still another probe tipnetwork as shown in FIG. 1.

[0024]FIG. 7C is a drawing of an embodiment of yet another probe tipnetwork as shown in FIG. 1.

[0025]FIG. 7D is a drawing of an embodiment of an additional probe tipnetwork as shown in FIG. 1.

[0026]FIG. 8A is a drawing of a transfer function vs. frequency of theparallel combination of the second resistor and the first capacitor ofFIG. 7A.

[0027]FIG. 8B is a drawing of a transfer function vs. frequency of theseries combination of the first resistor and the first capacitor of FIG.7A.

[0028]FIG. 8C is a drawing of a transfer function vs. frequency of theembodiment of the probe tip network shown in FIG. 7A.

[0029]FIG. 8D is a redrawing of the transfer function of a lossytransmission line vs. frequency as shown in FIG. 6. The transferfunction of FIG. 8D is for the uncompensated lossy transmission line.

[0030]FIG. 8E is a drawing of the transfer function for the combinationof the lossy transmission line compensated by the probe tip network ofFIG. 7A.

[0031]FIG. 9A is a drawing of a transfer function vs. frequency of theembodiment of the probe tip network shown in FIG. 7B.

[0032]FIG. 9B is a drawing of the transfer function for the combinationof the lossy transmission line compensated by the probe tip network ofFIG. 7B.

[0033]FIG. 10A is a drawing of a side view of an embodiment of adistributed capacitive/resistive electronic device consistent with theteachings of the invention.

[0034]FIG. 10B is a drawing of a top view of the distributedcapacitive/resistive electronic device of FIG. 10A.

[0035]FIG. 11A is a drawing of a side view of another embodiment of adistributed capacitive/resistive electronic device consistent with theteachings of the invention.

[0036]FIG. 11B is a drawing of a top view of the embodiment of thedistributed capacitive/resistive electronic device of FIG. 11A.

[0037]FIG. 12A is a drawing of a transfer function of the lossyconnecting transmission line of FIG. 3.

[0038]FIG. 12B is a drawing representative of the transfer function ofthe distributed capacitive/resistive electronic devices of FIGS. 10A-10Band 11A-11B.

[0039]FIG. 12C is a drawing of a transfer function an embodiment a lossyconnecting transmission line compensated by one of the distributedcapacitive/resistive electronic devices of FIGS. 10A-10B and 11A-11B.

DETAILED DESCRIPTION

[0040] As shown in the drawings for purposes of illustration, thepresent patent document relates to a novel method for the high-frequencycompensation of electronic devices, more specifically to thecompensation of frequency dependent losses in transmission lines.Previous methods have not been able to adequately compensate for suchfrequency dependent losses.

[0041] In the following detailed description and in the several figuresof the drawings, like elements are identified with like referencenumerals.

[0042] Lossy transmission line insertion loss cannot be adequatelycompensated by the use of a single zero or even by a couple pole-zerocompensations. As disclosed herein, one solution to this problem is acontinuously varying compensation technique comprising devices havingzeros distributed in frequency. In a representative embodiment, twothickfilm resistors are printed on a dielectric substrate therebycreating a parallel plate capacitor between the resistive elements. Oneresistor has mating contacts at both ends. The other resistor onlyconnects to the primary resistor at one end. The two resistors, whenplaced adjacent to or over each other, create a parallel-plate capacitorthat is distributed along the length of the resistors. The capacitorplates comprise resistive material resulting in a lossy distributedcapacitor. The geometries of the resistors and thickness of thethickfilm substrate, as well as its dielectric constant, determine thecapacitance between the resistive elements. The resistive pasteparameters, as well as the thickness of the paste and the geometriesused, determine the resistance of the resistors and controls the degreeof loss in the capacitive coupling. By controlling the geometriesinvolved and the resistive paste used, the response can be shaped tocompensate for transmission line insertion losses. Instead of asingle-zero compensation, this circuit yields a multi-pole-zerocompensation of a distributed nature.

[0043] Discrete components can create a piece-wise, approximatecompensation for the cable losses. However, such approaches typicallyare cumbersome due to the number of discrete components involved, thephysical space required for such a technique, and the inherentparasitics involved with multiple discrete components. As disclosedherein, a discrete component that is a continuous approximation of thecable loss instead of a piece-wise approximation of the cable loss canreduce the complexity of the compensation circuitry.

[0044]FIG. 1 is a drawing of a block diagram of an embodiment of acompensated probe network 5 consistent with the teachings of the presentpatent document. In FIG. 1, a probe tip network 10 is capable ofdetecting a signal from a system under test. A connecting transmissionline 20 is connected to the probe tip network 10 at one end. At theother end of the connecting transmission line 20, the connectingtransmission line 20 is connected to one end of a termination network30. At the other end of the termination network 30, the terminationnetwork 30 is connected to an amplifier 40. The probe tip network 10detects a signal from the system under test and transfers it to theconnecting transmission line 20 which in turn transfers the signal tothe termination network 30 which in its turn transfers the signal to theamplifier 40. The probe tip network 10 compensates for the frequencydependent transfer function of the connecting transmission line 20. Thetermination network 30 appropriately terminates connecting transmissionline 20 to reduce signal reflections at amplifier 40. The amplifier 40reproduces the detected signal for the end-use device which could be,for example, an oscilloscope or a logic analyzer.

[0045]FIG. 2 is a drawing of an embodiment of a probe tip network 10 asshown in FIG. 1. In FIG. 2, the probe tip network 10 is a passiveresistive-divider probe 10 which comprises a resistor R_(TIP). Thesignal from the system under test is detected with respect to systemground 50 and transferred to the connecting transmission line 20 alsowith respect to system ground 50.

[0046]FIG. 3 is a drawing of an embodiment of a connecting transmissionline 20 as shown in FIG. 1. In representative embodiments the connectingtransmission line 20 is fabricated as either a coaxial cable, a stripline, a microstrip, or a waveguide. FIG. 3 indicates a coaxial cablewherein the system ground 50 is the outer shield of the coaxal cable.

[0047]FIG. 4 is a drawing of an embodiment of a termination network 30as shown in FIG. 1. In the representative embodiment of FIG. 4, thetermination network 30 comprises terminating resistor R_(T).

[0048]FIG. 5 is a drawing of an embodiment of an amplifier 40 as shownin FIG. 1. In the representative embodiment of FIG. 1, the amplifier 40comprises a generic amplifier.

[0049] For an ideal lossless connecting transmission line 20,terminating resistor R_(T) is set to a value such that the parallelcombination of the input impedance of the amplifier 40 and terminatingresistor R_(T) matches the characteristic impedance of the connectingtransmission line 20 thereby eliminating signal reflections at theamplifier 40 end of the connecting transmission line 20. The connectingtransmission line 20 then presents the characteristic impedance of theconnecting transmission line 20 at its connection to the probe tipnetwork 10. For this ideal case, the characteristic impedance of theconnecting transmission line 20 is resistive, and therefore has nofrequency dependence. The resistor R_(TIP) is made sufficiently largesuch that the series combination of R_(TIP) and the characteristicimpedance of the connecting transmission line 20 does not significantlyload down the system under test. A typical choice for the seriescombination of resistor R_(TIP) and the characteristic impedance of theconnecting transmission line 20 is 10 times that of the impedance of thesystem under test at the point to which the probe tip network 10 isattached. For such a choice, the attachment of the probe tip network 10to the system under test typically does not significantly alter thefunctioning of the system under test.

[0050] In real systems, however, the connecting transmission line 20 isnot lossless but has a loss distributed throughout its length. FIG. 6 isa drawing of a transfer function of a lossy transmission line 20 vs.frequency of the embodiment of the connecting transmission line 20 asshown in FIG. 3. The transfer function of the lossy connectingtransmission line 20 falls off at approximately 20 db per decade offrequency.

[0051] Various embodiments of probe tip networks 10 as shown in FIG. 1are shown in FIGS. 7A-7D.

[0052]FIG. 7A is a drawing of an embodiment of another probe tip network10 as shown in FIG. 1. In FIG. 7A, the probe tip network 10 comprises afirst resistor R1 in series with a parallel combination of a secondresistor R2 and a first capacitor C1. The signal from the system undertest is detected with respect to system ground 50 and transferred to theconnecting transmission line 20 also with respect to system ground 50.

[0053]FIG. 7B is a drawing of an embodiment of still another probe tipnetwork 10 as shown in FIG. 1. In FIG. 7B, the probe tip network 10comprises a first resistor R1 in series with a parallel combination of asecond resistor R2 and a first capacitor C1 and further in series with aparallel combination of a third resistor R3 and a second capacitor C2.The signal from the system under test is detected with respect to systemground 50 and transferred to the connecting transmission line 20 alsowith respect to system ground 50.

[0054]FIG. 7C is a drawing of an embodiment of yet another probe tipnetwork 10 as shown in FIG. 1. In FIG. 7C, the probe tip network 10comprises a series of resistors R11 . . . R1n shunted variously by aseries of capacitors Ci1 . . . C1n.

[0055]FIG. 7D is a drawing of an embodiment of an additional probe tipnetwork 10 as shown in FIG. 1. FIG. 7D differs from FIG. 7C in that eachof a series of resistors R2 . . . R2n connects between the capacitorsC11 . . . C1n.

[0056] Various transfer functions associated with the embodiments of theprobe tip network 10 of FIG. 7A are shown in FIGS. 8A-8E. Once again inFIG. 7A, the probe tip network 10 comprises a first resistor R1 inseries with a parallel combination of a second resistor R2 and a firstcapacitor C1. FIG. 8A is a drawing of a transfer function vs. frequencyof the parallel combination of the second resistor R2 and the firstcapacitor C1 of FIG. 7A. In FIG. 8A, the transfer function of theparallel combination of second resistor R2 and first capacitor C1 has azero at frequency f1 wherein f1=1/(2πCR2*C1).

[0057]FIG. 8B is a drawing of a transfer function vs. frequency of theseries combination of the first resistor R1 and the first capacitor C1of FIG. 7A. In contrast to the zero in the transfer function of FIG. 8A,in FIG. 8B the transfer function of the parallel combination of firstresistor R1 and first capacitor C1 has a pole at frequency f2 whereinf2=1/(2πR1*C1).

[0058]FIG. 8C is a drawing of a transfer function vs. frequency of theembodiment of the probe tip network 10 shown in FIG. 7A. By setting thevalue of f2 to be greater than that of f1 via the appropriate selectionof values for R1, R2, and C1, the transfer function at frequenciesgreater than f1 will be larger than that of the transfer function belowf1. The actual value of the transfer function at the higher frequenciesrelative to that of the lower frequencies is dependent upon the value off2 relative to the value of f1.

[0059]FIG. 8D is a redrawing of the transfer function of a lossytransmission line vs. frequency as shown in FIG. 6. The transferfunction of FIG. 8D is for the uncompensated lossy transmission line 20.

[0060]FIG. 8E is a drawing of the transfer function for the combinationof the lossy transmission line 20 compensated by the probe tip network10 of FIG. 7A. The resulting “gain” of the pole-zero pair transferfunction can be used to extend the useful bandwidth of the lossyconnecting transmission line 20.

[0061] The technique of FIG. 7A is extended in FIG. 7B. The additionalparallel combination of third resistor R3 and second resistor C2 providean additional pole-zero compensation pair. The second zero occurs atf3=1/(2πR3*C2) with the second pole at f4=1/(2π(R1+R2)*C3).

[0062] Various transfer functions associated with the embodiments of theprobe tip network 10 of FIG. 7B are shown in FIGS. 9A-9B. Once again inFIG. 7B, the probe tip network 10 comprises the first resistor R1 inseries with the parallel combination of the second resistor R2 and thefirst capacitor C1, all of which are in series with the parallelcombination of the third resistor R3 and the second capacitor C2.

[0063]FIG. 9A is a drawing of a transfer function vs. frequency of theembodiment of the probe tip network 10 shown in FIG. 7B. By setting thevalue of f4 to be greater than that of f3, the value of f3 to be greaterthan that of f2, and the value of f2 to be greater than that of f1 byappropriate selection of values for R1, R2, R3, C1, and C2, the transferfunction at frequencies greater than f4 will be larger than that of thetransfer function between f3 and f2, and the transfer function atfrequencies between f3 and f2 will be larger than that of the transferfunction at frequencies less than f1. The actual values of the transferfunction at the higher and mid-range frequencies relative to that of thelower frequencies is dependent upon the value of f4 relative to thevalue of f3 and upon the value of f2 relative to the value of f1.

[0064]FIG. 9B is a drawing of the transfer function for the combinationof the lossy transmission line 20 compensated by the probe tip network10 of FIG. 7B. The resulting “gain” of the two pole-zero pair transferfunction can be used to extend the useful bandwidth of the lossyconnecting transmission line 20 to a greater extent than can thetransfer function of the single pole-zero pair of FIG. 7A.

[0065] The compensation techniques of FIGS. 8A and 8B could be extendedto even greater frequencies by the inclusion of additional parallelpairs of a resistor and a capacitor with appropriately chosen pole-zerofrequencies. However, the size and associated parasitic capacitances ofsuch probe tip networks 10 fabricated using discrete components makessuch extensions impractical.

[0066]FIG. 10A is a drawing of a side view of an embodiment of adistributed capacitive/resistive electronic device 1010 consistent withthe teachings of the invention. The electronic device 1010 comprises adielectric substrate 1015 on which a first resistive component 1020 isaffixed to a first side 1025 of the dielectric substrate 1015 and onwhich a second resistive component 1030 is affixed to a second side 1035of the dielectric substrate 1015. The second side 1035 is oppositelylocated from the first side 1025. The distributed capacitive/resistiveelectronic device 1010 further comprises a connecting component 1040affixed to the dielectric substrate 1015. The connecting component 1040further electrically connects the first resistive component 1020 to thesecond resistive component 1030 and is electrically connectable to otherelectronic circuitry, as for example the connecting transmission line20. At a location 1045 removed from the connecting component 1040, thesecond resistive component 1030 is electrically connectable toadditional electronic circuitry, as for example the system under test.The capacitive/resistive electronic device 1010 could be fabricated bystandard thick film techniques, wherein the first and second resistivecomponents 1020,1030 comprise resistive pastes affixed to the dielectricsubstrate 1015 via common thick film screening processes which are wellknown in the art. Typically the second resistive component 1030 has ahigher resistivity than does the first resistive component 1020. Theconnecting component 1040 could be affixed to the dielectric substrate1015 through a hole drilled in the dielectric substrate 1015 which issubsequently electroplated prior to the screening of the first andsecond resistive components 1020,1030. The connecting component 1040could also be affixed to the dielectric substrate 1015 through thedrilled hole in the dielectric substrate 1015 and then a conductivepaste screened through the hole to make contact to the first and secondresistive components 1020,1030. Connection between the connectingcomponent 1040 and the first and second resistive components 1020,1030could also be effected via screening or electroplating around the end ofthe dielectric substrate 1015 without use of a drilled hole. Other meansare also possible.

[0067]FIG. 10B is a drawing of a top view of the distributedcapacitive/resistive electronic device 1010 of FIG. 10A. In FIG. 10B,the first resistive component 1020 is non-uniformly distributed thelength of the electronic device 1010 with respect to the secondresistive component 1030. For illustrative purposes the first resistivecomponent 1020 is shown having greater width near the connectingcomponent 1040 than that of the second resistive component 1030.However, the width of first resistive component 1020 could be the sameas or less than that of the second resistive component 1030 near theconnecting component 1040. Also in FIG. 10B, the dielectric substrate1015 is shown as having a width greater than that of both the first andsecond resistive components 1020,1030. However, the width of thedielectric substrate 1015 could be equal to the width of the wider ofthe first and second resistive components 1020,1030. Connection betweenthe connecting component 1040 and the first and second resistivecomponents 1020,1030 could be effected as described above. Also, in FIG.10B, the first resistive component 1020 is shown as a triangle. However,the geometry of the first resistive component 1020 could be any othergeometry, including that of a rectangle or square, found to be suitablefor compensating for the lossy connecting transmission line 20. Furtherin FIG. 10B, the second resistive component 1030 is shown as arectangle. However, the geometry of the second resistive component 1030could be any other geometry, including that of a triangle or square,found to be suitable for compensating for the lossy connectingtransmission line 20

[0068] The equivalent circuit of the distributed capacitive/resistiveelectronic device 1010 of FIGS. 10A-10B is the circuit of FIG. 7C forthe case in which the second resistive component 1030 is highlyconductive relative to the first resistive component 1020. For this casethe resistivity of the first resistive component 1020 is typically atleast ten times greater than that of the second resistive component1030. In representative embodiments, the second resistive component 1030is fabricated from a metal.

[0069]FIG. 11A is a drawing of a side view of another embodiment of adistributed capacitive/resistive electronic device 1110 consistent withthe teachings of the invention. The electronic device 1110 comprises adielectric substrate 1115 on which a first resistive component 1120 isaffixed to a first side 1125 of the dielectric substrate 1115 and onwhich a second resistive component 1130 is affixed to a second side 1135of the dielectric substrate 1115. The second side 1135 is oppositelylocated from the first side 1125. The distributed capacitive/resistiveelectronic device 1110 further comprises a connecting component 1140affixed to the dielectric substrate 1115. The connecting component 1140further electrically connects the first resistive component 1120 to thesecond resistive component 1130 and is electrically connectable to otherelectronic circuitry, as for example the connecting transmission line20. At a location 1145 removed from the connecting component 1140, thesecond resistive component 1130 is electrically connectable toadditional electronic circuitry, as for example the system under test.The capacitive/resistive electronic device 1110 could be fabricated bystandard thick film techniques, wherein the first and second resistivecomponents 1120,1130 comprise resistive pastes affixed to the dielectricsubstrate 1115 via common thick film screening processes which are wellknown in the art. Typically the second resistive component 1130 has ahigher resistivity than does the first resistive component 1120. Theconnecting component 1140 could be affixed to the dielectric substrate1115 through a hole drilled in the dielectric substrate 1115 which issubsequently electroplated prior to the screening of the first andsecond resistive components 1120,1130. The connecting component 1140could also be affixed to the dielectric substrate 1115 through thedrilled hole in the dielectric substrate 1115 and then a conductivepaste screened through the hole to make contact to the first and secondresistive components 1120,1130. Connection between the connectingcomponent 1140 and the first and second resistive components 1120,1130could also be effected via screening or electroplating around the end ofthe dielectric substrate 1115 without use of a drilled hole. Other meansare also possible.

[0070]FIG. 11B is a drawing of a top view of the embodiment of thedistributed capacitive/resistive electronic device 1110 of FIG. 11A. Inthe representative embodiment of FIG. 11B, the first and secondresistive components 1120,1130 are uniformly distributed the length ofthe electronic device 1110. For illustrative purposes the firstresistive component 1120 is shown having greater width than that of thesecond resistive component 1130. However, the width of first resistivecomponent 1120 could be the same as or less than that of the secondresistive component 1130. Also in FIG. 11B, the dielectric substrate1115 is shown as having a width greater than that of both the first andsecond resistive components 1120,1130. However, the width of thedielectric substrate 1115 could be equal to the width of the wider ofthe first and second resistive components 1120,1130. Connection betweenthe connecting component 1140 and the first and second resistivecomponents 1120,1130 could be effected as described above. Further inFIG. 11B, the first resistive component 1120 is shown as a rectangle.However, the geometry of the first resistive component 1120 could be anyother geometry, including that of a triangle or square, found to besuitable for compensating for the lossy connecting transmission line 20.In addition, the second resistive component 1130 is shown as arectangle. However, the geometry of the second resistive component 1130could be any other geometry, including that of a triangle or square,found to be suitable for compensating for the lossy connectingtransmission line 20.

[0071] The equivalent circuit of the distributed capacitive/resistiveelectronic device 1110 of FIGS. 11A-11B is the circuit of FIG. 7D.

[0072]FIG. 12A is a drawing of a transfer function of the lossyconnecting transmission line 20 of FIG. 3. FIG. 12B is a drawingrepresentative of the transfer function of the distributedcapacitive/resistive electronic devices 1010,1110 of FIGS. 10A-10B and11A-11B. FIG. 12C is a drawing of a transfer function an embodiment alossy connecting transmission line 20 compensated by one of thedistributed capacitive/resistive electronic devices 1010,1110 of FIGS.10A-10B and 11A-11B. Note that depending upon design parameters chosen,the distributed capacitive/resistive electronic devices 1010,1110 ofFIGS. 10A-10B and 11A-11B can more closely compensate for the frequencydependence of the lossy connecting transmission line 20 over a frequencyrange of interest than can the discrete probe tip networks of FIGS.7A-7B.

[0073] Determination of the values of the components, includinggeometries, of the distributed capacitive/resistive electronic devices1010,1110 of FIGS. 10A-10B and 11A-11B may be determined empirically andanalytically via discrete component approximations.

[0074] A primary advantage of representative embodiments as described inthe present patent document over prior devices is the ability to moreclosely compensate for the frequency dependent losses introduced by alossy transmission line 20.

[0075] Other possible variations in the specific embodiments disclosedare possible. It is understood that although particular embodiments ofthe invention have been described and illustrated herein, it isrecognized that modifications and variations may readily occur to thoseskilled in the art and consequently, it is intended that the claims beinterpreted to cover such modifications and equivalents.

What is claimed is:
 1. An electronic device, comprising: a dielectricsubstrate; a first resistive component, wherein the first resistivecomponent is affixed to a first side of the dielectric substrate; asecond resistive component, wherein the second resistive component isaffixed to a second side of the dielectric substrate, wherein the secondside is oppositely located from the first side; a connecting component,wherein the connecting component is affixed to the dielectric substrate,wherein the connecting component electrically connects the firstresistive component to the second resistive component, wherein theconnecting component is electrically connectable to other electroniccircuitry, and wherein, at a location removed from the connectingcomponent, the second resistive component is electrically connectable toother electronic circuitry.
 2. The electronic device as recited in claim1, wherein the first and second resistive components are resistivepastes deposited onto the dielectric substrate via a thickfilm screeningprocess.
 3. The electronic device as recited in claim 1, wherein thefirst and second resistive components form the plates of a distributedcapacitor.
 4. The electronic device as recited in claim 1, wherein theconnecting component is capable of attachment to a transmission line andwherein at the location removed from the connecting component the secondresistive component is capable of attachment to electronic circuitry. 5.The electronic device as recited in claim 4, wherein the transmissionline is selected from the group consisting of a coax cable, a waveguide,and a microstrip.
 6. The electronic device as recited in claim 4,wherein the transmission line is lossy.
 7. The electronic device asrecited in claim 6, wherein the electronic device yields multiple-zerosdistributed in frequency so as to substantially compensate for themultiple-pole frequency transfer characteristic of the lossytransmission line over a preselected range of frequencies.
 8. Theelectronic device as recited in claim 1, wherein the connectingcomponent is capable of attachment to a transmission line and wherein atthe location removed from the connecting component the second resistivecomponent is capable of attachment to a system under test.
 9. Theelectronic device as recited in claim 8, wherein the transmission lineis selected from the group consisting of a coax cable, a waveguide, anda microstrip.
 10. The electronic device as recited in claim 8, whereinthe transmission line is lossy.
 11. The electronic device as recited inclaim 10, wherein the electronic device yields multiple-zerosdistributed in frequency so as to substantially compensate for themultiple-pole frequency transfer characteristic of the lossytransmission line over a preselected range of frequencies.
 12. Theelectronic device as recited in claim 1, wherein the resistivity of thefirst resistive component is greater than ten times the resistivity ofthe second resistive component.
 13. The electronic device as recited inclaim 12, wherein the geometry of the first resistive component isselected from the group consisting of a rectangle, a square, and atriangle.
 14. The electronic device as recited in claim 12, wherein thegeometry of the second resistive component is selected from the groupconsisting of a rectangle, a square, and a triangle.
 15. The electronicdevice as recited in claim 12, wherein the material from which thesecond resistive component is fabricated is a metal.
 16. The electronicdevice as recited in claim 1, wherein the geometry of the firstresistive component is selected from the group consisting of arectangle, a square, and a triangle.
 17. The electronic device asrecited in claim 1, wherein the geometry of the second resistivecomponent is selected from the group consisting of a rectangle, asquare, and a triangle.
 18. The electronic device as recited in claim 1,wherein the material from which the second resistive component isfabricated is a metal.